bouncycastle — security advisory
In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.
- Products
- bouncycastle
- Affected versions
- Not specified
- Fixed versions
- 1.61-1
- CVEs
- CVE-2020-26939
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 13:45 UTC · Revision 1
Source evidence
In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.
osv:DEBIAN-CVE-2020-26939
bouncycastle
Fixed versions: 1.61-1
bouncycastle
Fixed versions: 1.61-1
bouncycastle
Fixed versions: 1.61-1
Complete source record
{
"id": "2ee8467c8a163604c1c8a59108b518fb9e7c8f7cb83f77b84fdd54b6764afb32",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-26939",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2020-26939",
"summary": "In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.",
"evidence": "osv:DEBIAN-CVE-2020-26939",
"products": [
{
"name": {
"value": "bouncycastle",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.61-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "bouncycastle",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.61-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "bouncycastle",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.61-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2020-26939",
"aliases": [
"DEBIAN-CVE-2020-26939"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.61-1"
}
]
}
],
"package": {
"name": "bouncycastle",
"purl": "pkg:deb/debian/bouncycastle?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.61-1"
}
]
}
],
"package": {
"name": "bouncycastle",
"purl": "pkg:deb/debian/bouncycastle?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.61-1"
}
]
}
],
"package": {
"name": "bouncycastle",
"purl": "pkg:deb/debian/bouncycastle?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T12:02:41.469943272Z",
"provider": "osv",
"upstream": [
"CVE-2020-26939"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2020-26939"
]
},
"related_cves": [
{
"value": "CVE-2020-26939",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 452770,
"published_at": "2020-11-02T22:15:13.393+00:00"
}